In an absorbent article such as a disposable diaper or disposable shorts, a structure to provide a so called leg gather is widely employed so as to fit to a leg-line portion corresponding to a leg of a wearer. In such absorbent article, a fitting to a wearer (in particular, a leg) can be ensured, since a leg gather expands and contracts in accordance of a shape of a leg-line portion or a movement of the wearer.
In general, as a method for manufacturing a leg gather according to a shape of leg-line portion, there is well known a method for disposing an elongated elastic member (for example, a fiber-shaped rubber) in an expanded state on a sheet-shaped continuum such as a web to be conveyed. Specifically, the elastic member can be disposed in a wavy shape having a predetermined amplitude on the continuum to be conveyed, by a swinging mechanism to feed the elastic member while swinging (reciprocally) along a cross direction crossing a conveyance direction of the continuum. The elastic member disposed in the wavy shape is adhered onto the continuum via an adhesive or the like, and the continuum thus adhered is cut in product size so that the shape of the elastic member fits to the shape of the leg-line portion of the wearer.
In addition, in disposable shorts or the like for incontinence at a light level, there is a need for a comfortable feeling of wearing of underwear or the like and thus it is preferable to have a further high feeling of fitting. Therefore, there is known a method for disposing a part of an elastic member that is to be disposed in a wavy shape by a swinging mechanism so as to deviate from a widthwise end portion of a continuum to the outside (for example, Patent Literature 1, pages 8 to 9, and FIG. 4). According to such a method, it becomes easy to dispose an elastic member in an entire region of a leg-line portion or to form the shape of the elastic member to further fit to the shape of the leg-line portion. It is to be noted that in this case, an elastic member that is not disposed on the continuum (an elastic member having deviates outboard of t the end of the continuum in widthwise direction) is cut and removed in the steps on a downstream side.
Incidentally, in recent years, in disposable diapers, there has been a so called three-piece disposable diaper to separately form a foreside region and a backside region, and joining the foreside region and the backside region with each other through an absorbent main body having an absorber (for example, refer to Patent Literature 2, FIGS. 2 to 4). When a leg-line elastic member such as a leg gather is disposed in a continuum constituting the foreside region, the step of disposing the elastic member in a continuum constituting the foreside region and the step of disposing the elastic member in a continuum constituting the backside region are provided.